Research On Optimization Problem On Container Yard Operation Scheduling

Port container yard, as an important tache of the process of container transportation, is required to be automated, unmanned and shortcuted as the trend of economization, simplification and standardization in container transportation. Therefore, it is necessary to improve the operation efficiency of container yard. This paper focuses on two main operations of the gate side of container yards: pick-up operation and storage space allocation operation on the gate side of container yards, whose scheduling efficiency has direct impact on the efficiency of truck's passing though the gate.This paper explained the factors of pick-up operation were included in which of storage space allocation firstly. Then, it was proposed to sovle the problem of storage space allocation in container yard by rule-based reasoning, the constraints factors of this operation were denoted as fact and rule, stored in the database and rule base respectively. The best position was gained by reasoning.Then, analyzed the pick-up operation process on the gate side of container yard for import containers, the optimization problem was attribute to be a muti-stage decision making problem. A mathematical model which aims to minimize the total cost of whole pick-up operation process is established, it was a multi-phase optimization model comprised of two sub-models: rehandling operation scheduling and the shortest path searching. A two-layer A* heuristic algorithm with the inner A* algorithm structure embedded into the outer one was put forward and realized, the inner one was responsible for searching the shortest path and the outer one for optimizing rehandling strategy.Evaluation and verification are proposed at last. A container allocation operation example shows that not only the container stack allocated according to the above method is convenient to shipment loading, but also in favor of saving the yard management cost. For pick-up operation, after comparing A* algorithm with Genetic algorithm for the same problem, the result shows that A* algorithm has better performance in optimization strategy and efficiency.The optimization algorithm of this paper, not only has it great value for application, but also supply a new method for similar problems.